The present invention relates to a ratchet wrench and a method of assembling the wrench, and more particularly to a ratchet wrench having three holes formed in the head and a rotatable detent means.
Many ratchet wrenches have been produced commercially and disclosed in patents. Most of the ratchet wrenches have two openings formed in the head of the wrench, a ratchet gear being disposed in one opening and a pawl being disposed in the other opening. Also, most ratchet wrenches have a blind bore formed in the handle of the wrench and oriented toward the opening in which is the pawl and ratchet gear are disposed. A spring and ball or other detent means is disposed in the blind bore. The detent means engages pockets in the pawl as the pawl is moved between a forward and a reverse position.
Production of these ratchet wrenches is comparatively costly because of the need to machine the blind bore in the handle of the wrench and to install a ball and spring detent means in the blind bore. The creating of the bore is time consuming and difficult because the bore must be machined at an angle due to the shape of the opening in the head of the wrench. Furthermore, assembly of the spring and ball in the bore requires special tooling. Also, most ratchet wrenches are made by forging and then milling openings in the head of the wrench and assembling the wrenches by inserting the ratchet gear and pawl from the top or bottom of the wrench. The detent means must be inserted laterally and within the bores and then held for pawl insertion. This also increases production costs. The applicant is aware of the following patents which do not have some of these limitations.
U.S. Pat. No. 2,978,081 to Lundin discloses a ratchet wrench having a head with removable top and bottom cover plates over two through holes. A manipulator has a ball and spring detent means mounted above the body of the wrench which pivots the detent means.
U.S. Pat. No. 3,490,317 to Rozmus discloses a ratchet wrench with three chambers, two of which accommodate drive gears. A reversible ratchet locking mechanism includes a pawl in a third cylindrical chamber and plunger biased by a spring which is disposed in a bore in the handle communicating with the third chamber. A lever moves the pawl to a selected position with respect to the plunger.
U.S. Pat. No. 4,328,720 to Shield discloses a socket wrench having three cavities in the head-handle, which is an integral piece only one of the cavities is cylindrical and the ratchet gear is disposed therein. The pawl is adjacent to the ratchet gear. An interior lever which contacts the pawl is in the third cavity and is controlled by an external latch handle. The device does not have a detent means within the interior lever. A cover is disposed over the cavities.
Diebert, in U.S. Pat. No. 4,336,728 discloses a reversible ratchet wrench having three partially overlapping recesses in the head with a toothed wheel in one recess, a pawl in an adjacent recess, and an actuator in the third recess. The actuator is driven by cams to engage the pawl and to determine the direction of rotation of the ratchet wheel. The pivotally mounted actuator carries a detent means in a bore within the actuator.
Dempsey et al, U.S. Pat. Nos. 4,491,043 and 4,553,453 disclose a wrench having three substantially cylindrical chambers having overlapping areas. A wheel placed in the first chamber communicates with a shifter pin in the second chamber. The shifter pin is manipulated by a knob in the third chamber.
Chow, in U.S. Pat. No. 4,862,775, discloses a ratchet wrench having an upper cover plate and a lower cover plate on a housing. A ratchet wheel, a pawl and a bifurcated control element are disposed in the housing. A resilient sheet is arranged between the pawl and the control element. The control element is pivoted in the housing and is manipulated by a button which slides, externally of the upper cover plate, through a slot in the upper cover plate.
U.S. Pat. No. 5,090,273 issued to Fossella discloses a ratchet wrench having three interconnecting chambers. One chamber is a through opening in which a toothed wheel is disposed. A pawl is received in one blind chamber and a pawl switching lever is disposed in the other blind chamber. The pawl switching lever is a spring-loaded plunger.
German Registration No. 1810811, June 1970 discloses a ratchet wrench having a detent means in a bore in the handle. The detent means engages alternate pockets in the rear face of a yoke. The yoke carries a tube with a ball and spring. The tube is connected to the pawl by a pin so that rotation of the yoke produces movement of the pawl between a forward and a reverse position.
These patents have existed for numerous years and have not achieved commercial success. There exists a need for a ratchet wrench which can be produced more economically.